1. Technical Field of the Invention
The present invention relates to a method of cutting a thin-walled material.
2. Description of the Related Art
In this application, a thin-walled material is, for example, a rotating body which rotates around a central axis, and means a material having a portion which is thin in thickness. The thin-walled material is, for example, a ring or a casing of an aircraft jet engine, which is made of Ti alloy, Ni alloy, or Al alloy. Also, the thin-walled material may also be a part having as a portion thereof a thin-walled portion which is a cutting target of the present invention.
At a rotating machine such as a jet engine, a gas turbine, or a supercharger, a rotating body such as a rotating shaft which rotates around a central axis is provided.
There is a case where the rotating body has an inner round surface and an outer round surface over a predetermined range in the direction parallel to the central axis. In this case, the rotating body is manufactured as follows. Rough cutting work of the inner round surface, rough cutting work of the outer round surface, semi-finish cutting work of the inner round surface, semi-finish cutting work of the outer round surface, finish cutting work of the inner round surface, and finish cutting work of the outer round surface are performed with respect to a material in this order.
In addition, as prior art documents of the present invention, Patent Documents 1 to 3 described below are given.    Patent Document 1: Japanese Patent Application Laid-Open No. 2008-036751    Patent Document 2: Japanese Patent Application Laid-Open No. 2003-103402    Patent Document 3: Japanese Patent No. 3057952
However, in the finish cutting work, since the wall thickness between the inner round surface and the outer round surface is made thin, chattering vibration or deformation easily occurs. Therefore, a chattering vibration preventing retainer is needed. That is, the finish cutting work of the inner round surface is performed in a state where the outer round surface is mounted on the chattering vibration preventing retainer, and thereafter, the finish cutting work of the outer round surface is performed in a state where the inner round surface is mounted on the chattering vibration preventing retainer.